Place these notes into your Biology Notebook. C 12 Notes Place these notes into your Biology Notebook.
Avery’s experiments showed that bacteria are transformed by DNA. In 1928, Frederick Griffith conducted an experiment with bacteria. He observed that when he injected a mixture of heat-killed, disease-causing bacteria and live harmless bacteria into mice they developed pneumonia. DNA is made up of deoxyribose (a sugar), + phosphate group (PO4), + nitrogenous base (Guanine, Cytosine, Adenine, or Thymine).
Because of base pairing in DNA, the percentage of pyrimidines in DNA is about equal to the percentage of purines. In eukaryotes, DNA is located in the nucleus. DNA is copied during a process called replication. RNA contains the sugar ribose. Unlike DNA, RNA contains uracil.
DNA replication results in two DNA molecules, each with one new strand and one original strand. During DNA replication, a DNA strand that has the bases CAAGTACGT produces a strand with the bases GTTCATGCA. DNA contains the following nitrogenous bases: adenine, thymine, guanine, and cytosine. RNA contains the following nitrogenous bases: adenine, uracil, guanine, and cytosine. There are three main types of RNA, mRNA, tRNA, and rRNA.
During replication, DNA molecules are copied. During transcription, RNA molecules are formed inside the nucleus.
The Genetic Code
How many bases are needed to specify four amino acids? 12 Why is it possible for an amino acid to be specified by more than one kind of codon? There are 64 different kinds of codons, but only 20 amino acids. Genes contain instructions for making proteins. Messenger RNA (mRNA) functions as a blueprint of the genetic code.
A mutation that involves one or a few nucleotides is called a point mutation. A promoter is a binding site for RNA polymerase. In E. coli, the lac operon controls the breakdown of lactose. A lac repressor turns off the lac genes by binding to the operator. Hox genes determine an animal’s basic body plan. Hox genes determine the location of a dog’s ears.
Standardized Test Prep During replication, the ______ sequence of nucleotides would bond with the DNA sequence of TATGA. ATACT RNA differs from DNA in that it contains the sugar ribose and the nitrogenous base uracil. Thymine and uracil will bond with adenine.
The process of decoding mRNA into a polypeptide chain is known as translation. DNA does NOT contain adenine-uracil pairs, only adenine-thymine pairs. Alfred Hershey and Martha Chase performed experiments with viruses called bacteriophages. They concluded that the genetic material of the bacteriophage was DNA, not protein.
Anticodons are part of the structure of transfer RNA (tRNA)
Percentage of Bases in Three Samples G C A T 35 15 B 40 10 25 U 35 15 B 40 10 25 Which sample(s) support the base pairing rules? Samples A and C If the scientist had analyzed mRNA rather than DNA, what percentage of uracil would you expect to find in Sample B? 10
Each of the lettered choices below refers to the following numbered statements. Select the best lettered choice. A choice may be used once, more than once, or not at all. Mutation (B) Double helix (C) Protein synthesis (D) Genetic code (E) Transcription RNA molecules are produced by copying part of the nucleotide sequence of DNA into a complementary sequence in RNA. Transcription
Each of the lettered choices below refers to the following numbered statements. Select the best lettered choice. A choice may be used once, more than once, or not at all. Mutation (B) Double helix (C) Protein synthesis (D) Genetic code (E) Transcription Structure of DNA Double helix
Each of the lettered choices below refers to the following numbered statements. Select the best lettered choice. A choice may be used once, more than once, or not at all. Mutation (B) Double helix (C) Protein synthesis (D) Genetic code (E) Transcription Heritable change in the DNA sequence that affects genetic information. Mutation